Star block copolymer

Abstract

A novel star block copolymer which can be made to have a high molecular weight and gives a solution having a lower viscosity than solutions of linear polymers having the same molecular weight as the copolymer and which is expected to be used as a resist material; and a process for producing the copolymer. The star block copolymer having alkenylphenol skeletons is obtained by homopolymerizing by living anion polymerization an alkenylphenol compound in which the hydroxyl group of the phenol moiety has been protected by a saturated aliphatic protective group or copolymerizing the alkenylphenol compound with a vinylaromatic compound by living anion polymerization, subsequently copolymerizing the resultant polymer using a polyfunctional coupling agent such as divinylbenzene to obtain a star block copolymer, and eliminating the saturated aliphatic protective groups with an acid reagent.

What is claimed is:  
     
       1. A star block copolymer characterized in that an arm moiety (A) comprises a polymer chain (A1) consisting of only a repeated unit represented by the general formula (I):                    
       wherein R 1  represents a hydrogen atom or a methyl group; R 2  represents a hydrogen atom or a C1 through C6 alkyl group; and p represents 1 or 2 wherein R 2  may be identical or different when p is 2, in the star block copolymer having the arm moiety composed of a central core and polymer chains extending from the central core; 
       or having a repeated unit represented by one of the general formulae (I) and (II):                    
       wherein R 3  represents a hydrogen atom or a methyl group; R 4  represents a C1 through C6 alkyl group; R 5  represents an acidolytic/leaving group; q represents 0, 1 or 2 wherein R 4  may be identical or different when q is 2; 
       the general formulae (I) and (III):                    
       wherein R 6  represents a hydrogen atom, a methyl group or an aryl group which may have substituents; R 7  represents a C1 through C6 alkyl group; r represents 0, 1 or 2 wherein R 7  may be identical or different when r is 2; and 
       the general formulae (I), (II) and (III):                    
       wherein R 3 , R 4 , R 5 , and q are the same as mentioned above. 
     
     
       2. The star block copolymer according to  claim 1 , characterized in that the arm moiety (A) has the polymer chain (A1) and a polymer chain (A2) having repeated units (A21) represented by one of: 
       the general formula (IV):                    
       wherein R 8  represents a hydrogen atom or a methyl group; and R 9  represents a hydrogen atom, a C1 through C12 alkyl group, a hydrocarbon group having alicyclic skeletons of C3 or more which may have substituents, an alkyl group having hydrocarbon groups having the alicyclic skeletons, or a heterocyclic group; and 
       the general formula (IV) and repeated units (A22) represented by the general formula (V):                    
       wherein R 10  is a hydrogen atom, a methyl group, or an aryl group which may have substituents; R 11  represents a C1 through C6 alkyl group, or OR 12  group wherein R 12  represents a hydrogen atom, a C1 through C6 alkyl group, or an acidolytic/leaving group; and t represents an integer of 0 or from 1 through 3 wherein R 11  may be identical or different when t is 2 or more. 
     
     
       3. The star block copolymer according to  claim 2 , characterized in that the polymer chain (A2) is a block copolymerized by (A22) through (A21) sequentially from the central core. 
     
     
       4. The star block copolymer according to  claim 1 , characterized in that the number average molecular weight of the polymer chains constituting the arm moiety is from 1,000 to 100,000 and the ratio (Mw/Mn) of the weight average molecular weight(Mw) to the number average molecular weight(Mn) is in the range of from 1.00 to 1.50. 
     
     
       5. The star block copolymer according to  claim 1 , characterized in that the central core is a core crosslinked with a polyfunctional coupling agent. 
     
     
       6. The star block copolymer according to  claim 5 , characterized in that the polyfunctional coupling agent is a compound having at least two polymerization double bonds per molecule. 
     
     
       7. The star block copolymer according to  claim 5 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 19 , and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       8. The star block copolymer according to  claim 1 , characterized in that the number average molecular weight is from 3,000 to 200,000. 
     
     
       9. A process for producing the star block copolymer according to  claim 1 , characterized in that by anionic polymerization using an anionic polymerization initiator as a polymerization initiator, after a compound represented by the general formula (VII):                    
       wherein R 3 , R 4 , R 5  and q are the same as mentioned above is homopolymerized or after the compound represented by the general formula (VII) and a compound capable of copolymerizing are copolymerized, further a polyfunctional coupling agent (C) is copolymerized, and then protective groups of phenol hydroxyl groups are eliminated. 
     
     
       10. The process for producing the star block copolymer according to  claim 9 , characterized in that the molar ratio is from 0.1 to 10 of the polyfunctional coupling agent (C) to an active end of the polymer chain homopolymerizing the compound represented by the general formula (VII) or an active end (D) of the polymer chain copolymerizing a compound capable of copolymerizing with the compound represented by the general formula (VII) by anionic polymerization using an anionic polymerization initiator as a polymerization initiator. 
     
     
       11. The process for producing the star block copolymer according to  claim 9 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 19 , and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2: and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       12. The process for producing the star block copolymer according to  claim 9 , characterized in that the compound capable of copolymerizing with the compound represented by the general formula (VII) is a compound represented by the general formula (VIII):                    
       wherein R 6 , R 7 , and r are the same as mentioned above. 
     
     
       13. The process for producing the star block copolymer according to  claim 9 , characterized in that the compound capable of anion polymerizing is a compound represented by the general formula (IX):                    
       wherein R 8  and R 9  are the same as mentioned above. 
     
     
       14. A star block copolymer characterized in that an arm moiety (A) comprises a polymer chain (A1) having a repeated unit represented by one of 
       the general formula (I):                    
       wherein R 1  represents a hydrogen atom or a methyl group; R 2  represents a hydrogen atom or a C1 through C6 alkyl group; and p represents 1 or 2 wherein R 2  may be identical or different when p is 2, in the star block copolymer having the arm moiety composed of a central core and polymer chains extending from the central core; 
       the general formulae (I) and (II):                    
       wherein R 3  represents a hydrogen atom or a methyl group; R 4  represents a C1 through C6 alkyl group; R 5  represents an acidolytic/leaving group; q represents 0, 1 or 2 wherein R 4  may be identical or different when q is 2; 
       the general formulae (I) and (III):                    
       wherein R 6  represents a hydrogen atom, a methyl group or an aryl group which may have substituents; R 7  represents a C1 through C6 alkyl group; r represents 0, 1 or 2 wherein R 7  may be identical or different when r is 2; and 
       the general formulae (I), (II) and (III):                    
       wherein R 3 , R 4 , R 5 , and q are the same as mentioned above, and 
       wherein the arm moiety (A) has the polymer chain (A1) and a polymer chain (A2) having repeated units (A21) represented by one of:  
       the general formula (IV):                    
       wherein R 8  represents a hydrogen atom or a methyl group; and R 9  represents a hydrogen atom, a C1 through C12 alkyl group, a hydrocarbon group having alicyclic skeletons of C3 or more which may have substituents, an alkyl group having hydrocarbon groups having the alicyclic skeletons, or a heterocyclic group; and 
       the general formula (IV) and repeated units (A22) represented by the general formula (V):                    
       wherein R 10  is a hydrogen atom, a methyl group, or an aryl group which may have substituents; R 11 represents a C1 through C6 alkyl group, or OR 12  group wherein R 12  represents a hydrogen atom, a C1 through C6 alkyl group, or an acidolytic/leaving group; and t represents an integer of 0 or from 1 through 3 wherein R 11  may be identical or different when t is 2 or more. 
     
     
       15. The star block copolymer according to  claim 14 , characterized in that the polymer chain (A2) is a block copolymerized by (A22) through (A21) sequentially from the central core. 
     
     
       16. The star block copolymer according to  claim 14 , characterized in that the number average molecular weight of the polymer chains constituting the arm moiety is from 1,000 to 100,000 and the ratio (Mw/Mn) of the weight average molecular weight(Mw) to the number average molecular weight(Mn) is in the range of from 1.00 to 1.50. 
     
     
       17. The star block copolymer according to  claim 14 , characterized in that the central core is a core crosslinked with a polyfunctional coupling agent. 
     
     
       18. The star block copolymer according to  claim 17 , characterized in that the polyfunctional coupling agent is a compound having at least two polymerization double bonds per molecule. 
     
     
       19. The star block copolymer according to  claim 17 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 19 , and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       20. The star block copolymer according to  claim 14 , characterized in that the number average molecular weight is from 3,000 to 200,000. 
     
     
       21. A process for producing the star block copolymer according to  claim 14 , characterized in that by anionic polymerization using an anionic polymerization initiator as a polymerization initiator, after a compound represented by the general formula (VI):                    
       wherein R 3 , R 4 , R 5  and q are the same as mentioned above is homopolymerized or after the compound represented by the general formula (VII) and a compound capable of copolymerizing are copolymerized, further a polyfunctional coupling agent (C) is copolymerized, and then protective groups of phenol hydroxyl groups are eliminated. 
     
     
       22. The process for producing the star block copolymer according to  claim 21 , characterized in that the molar ratio is from 0.1 to 10 of the polyfunctional coupling agent (C) to an active end of the polymer chain homopolymerizing the compound represented by the general formula (VII) or an active end (D) of the polymer chain copolymerizing a compound capable of copolymerizing with the compound represented by the general formula (VII) by anionic polymerization using an anionic polymerization initiator as a polymerization initiator. 
     
     
       23. The process for producing the star block copolymer according to  claim 21 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18  R 19  and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       24. The process for producing the star block copolymer according to  claim 21 , characterized in that the compound capable of copolymerizing with the compound represented by the general formula (VII) is a compound represented by the general formula (VIII):                    
       wherein R 6 , R 7 , and r are the same as mentioned above. 
     
     
       25. The process for producing the star block copolymer according to  claim 21 , characterized in that the compound capable of anion polymerizing is a compound represented by the general formula (IX):                    
       wherein R 8  and R 9  are the same as mentioned above. 
     
     
       26. A star block copolymer characterized in that an arm moiety (A) comprises a polymer chain (A1) having a repeated unit represented by one of the general formula (I):                    
       wherein R 1  represents a hydrogen atom or a methyl group; R 2  represents a hydrogen atom or a C1 through C6 alkyl group; and p represents 1 or 2 wherein R 2  may be identical or different when p is 2, in the star block copolymer having the arm moiety composed of a central core and polymer chains extending from the central core; 
       the general formulae (I) and (II):                    
       wherein R 3  represents a hydrogen atom or a methyl group; R 4  represents a C1 through C6 alkyl group; R 5  represents an acidolytic/leaving group; q represents 0, 1 or 2 wherein R 4  may be identical or different when q is 2; 
       the general formulae (I) and (III):                    
       wherein R 6  represents a hydrogen atom, a methyl group or an aryl group which may have substituents; R 7  represents a C1 through C6 alkyl group; r represents 0, 1 or 2 wherein R 7  may be identical or different when r is 2; and 
       the general formulae (I), (II) and (III):                    
       wherein R 3 , R 4 , R 5 , and q are the same as mentioned above, 
       characterized in that by anionic polymerization using an anionic polymerization initiator as a polymerization initiator, after a compound represented by the general formula (VII):                    
       wherein R 3 , R 4 , R 5  and q are the same as mentioned above is homopolymerized or after the compound represented by the general formula (VII) and a compound capable of copolymerizing are copolymerized, further a polyfunctional coupling agent (C) is copolymerized, and then protective groups of phenol hydroxyl groups are eliminated. 
     
     
       27. The star block copolymer according to  claim 26 , characterized in that the arm moiety (A) has the polymer chain (A1) and a polymer chain (A2) having repeated units (A21) represented by one of: 
       the general formula (IV):                    
       wherein R 8  represents a hydrogen atom or a methyl group; and R 9  represents a hydrogen atom, a C1 through C12 alkyl group, a hydrocarbon group having alicyclic skeletons of C3 or more which may have substituents, an alkyl group having hydrocarbon groups having the alicyclic skeletons, or a heterocyclic group; and 
       the general formula (IV) and repeated units (A22) represented by the general formula (V):                    
       wherein R 10  is a hydrogen atom, a methyl group, or an aryl group which may have substituents; R 11  represents a C1 through C6 alkyl group, or OR 12  group wherein R 12  represents a hydrogen atom, a C1 through C6 alkyl group, or an acidolytic/leaving group; and t represents an integer of 0 or from 1 through 3 wherein R 11  may be identical or different when t is 2 or more. 
     
     
       28. The star block copolymer according to  claim 27 , characterized in that the polymer chain (A2) is a block copolymerized by (A22) through (A21) sequentially from the central core. 
     
     
       29. The star block copolymer according to  claim 26 , characterized in that the number average molecular weight of the polymer chains constituting the arm moiety is from 1,000 to 100,000 and the ratio (Mw/Mn) of the weight average molecular weight(Mw) to the number average molecular weight(Mn) is in the range of from 1.00 to 1.50. 
     
     
       30. The star block copolymer according to  claim 26 , characterized in that the central core is a core crosslinked with a polyfunctional coupling agent. 
     
     
       31. The star block copolymer according to  claim 30 , characterized in that the polyfunctional coupling agent is a compound having at least two polymerization double bonds per molecule. 
     
     
       32. The star block copolymer according to  claim 30 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 19 , and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       33. The star block copolymer according to  claim 26 , characterized in that the number average molecular weight is from 3,000 to 200,000. 
     
     
       34. The process for producing the star block copolymer according to  claim 26 , characterized in that the molar ratio is from 0.1 to 10 of the polyfunctional coupling agent (C) to an active end of the polymer chain homopolymerizing the compound represented by the general formula (VII) or an active end (D) of the polymer chain copolymerizing a compound capable of copolymerizing with the compound represented by the general formula (VII) by anionic polymerization using an anionic polymerization initiator as a polymerization initiator. 
     
     
       35. The process for producing the star block copolymer according to  claim 26 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 19 , and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       36. The process for producing the star block copolymer according to  claim 26 , characterized in that the compound capable of copolymerizing with the compound represented by the general formula (VII) is a compound represented by the general formula (VIII):                    
       wherein R 6 , R 7 , and r are the same as mentioned above. 
     
     
       37. The process for producing the star block copolymer according to  claim 26 , characterized in that the compound capable of anion polymerizing is a compound represented by the general formula (IX):                    
       wherein R 8  and R 9  are the same as mentioned above. 
     
     
       38. A star block copolymer characterized in that an arm moiety (A) comprises a polymer chain (A1) having a repeated unit represented by one of 
       the general formula (I):                    
       wherein R 1  represents a hydrogen atom or a methyl group; R 2  represents a hydrogen atom or a C1 through C6 alkyl group; and p represents 1 or 2 wherein R 2  may be identical or different when p is 2, in the star block copolymer having the arm moiety composed of a central core and polymer chains extending from the central core; 
       the general formulae (I) and (II):                    
       wherein R 3  represents a hydrogen atom or a methyl group; R 4  represents a C1 through C6 alkyl group; R 5  represents an acidolytic/leaving group; q represents 0, 1 or 2 wherein R 4  may be identical or different when q is 2; 
       the general formulae (I) and (III):                    
       wherein R 6  represents a hydrogen atom, a methyl group or an aryl group which may have substituents; R 7  represents a C1 through C6 alkyl group; r represents 0, 1 or 2 wherein R 7  may be identical or different when r is 2; and 
       the general formulae (I), (II) and (III):                    
       wherein R 3 , R 4 , R 5 , and q are the same as mentioned above, and 
       wherein the central core is a core crosslinked with a polyfunctional coupling agent.  
     
     
       39. The star block copolymer according to  claim 38 , characterized in that the arm moiety (A) has the polymer chain (A1) and a polymer chain (A2) having repeated units (A21) represented by one of: 
       the general formula (IV):                    
       wherein R 8  represents a hydrogen atom or a methyl group; and R 9  represents a hydrogen atom, a C1 through C12 alkyl group, a hydrocarbon group having alicyclic skeletons of C3 or more which may have substituents, an alkyl group having hydrocarbon groups having the alicyclic skeletons, or a heterocyclic group; and 
       the general formula (IV) and repeated units (A22) represented by the general formula (V):                    
       wherein R 10  is a hydrogen atom, a methyl group, or an aryl group which may have substituents; R 11  represents a C1 through C6 alkyl group, or OR 12  group wherein R 12  represents a hydrogen atom, a C1 through C6 alkyl group, or an acidolytic/leaving group; and t represents an integer of 0 or from 1 through 3 wherein R 11  may be identical or different when t is 2 or more. 
     
     
       40. The star block copolymer according to  claim 39 , characterized in that the polymer chain (A2) is a block copolymerized by (A22) through (A21) sequentially from the central core. 
     
     
       41. The star block copolymer according to  claim 38 , characterized in that the number average molecular weight of the polymer chains constituting the arm moiety is from 1,000 to 100,000 and the ratio (Mw/Mn) of the weight average molecular weight(Mw) to the number average molecular weight(Mn) is in the range of from 1.00 to 1.50. 
     
     
       42. The star block copolymer according to  claim 38 , characterized in that the polyfunctional coupling agent is a compound having at least two polymerization double bonds per molecule. 
     
     
       43. The star block copolymer according to  claim 38 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups, or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 18 , and R 20  represent C1 through C6 alkyl groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       44. The star block copolymer according to  claim 38 , characterized in that the number average molecular weight is from 3,000 to 200,000. 
     
     
       45. A process for producing the star block copolymer according to  claim 38 , characterized in that by anionic polymerization using an anionic polymerization initiator as a polymerization initiator, after a compound represented by the general formula (VII):                    
       wherein R 3 , R 4 , R 5  and q are the same as mentioned above is homopolymerized or after the compound represented by the general formula (VII) and a compound capable of copolymerizing are copolymerized, further a polyfunctional coupling agent (C) is copolymerized, and then protective groups of phenol hydroxyl groups are eliminated. 
     
     
       46. The process for producing the star block copolymer according to  claim 45 , characterized in that the molar ratio is from 0.1 to 10 of the polyfunctional coupling agent (C) to an active end of the polymer chain homopolymerizing the compound represented by the general formula (VII) or an active end (D) of the polymer chain copolymerizing a compound capable of copolymerizing with the compound represented by the general formula (VII) by anionic polymerization using an anionic polymerization initiator as a polymerization initiator. 
     
     
       47. The process for producing the star block copolymer according to  claim 45 , characterized in that the polyfunctional coupling agent is a compound represented by the general formula (VI):                    
       wherein R 13  represents a hydrogen atom or a methyl group; Y represents an oxygen atom, a sulfur atom, R 16 N wherein R 16  represents a hydrogen atom, C1 through C6 alkyl groups or alkoxycarbonyl groups, a methylene group which may have substituents, a phenylene group which may have substituents, C(R 18 R 19 )O, C(R 18 R 19 )S, C(R 18 R 19 )N(R 20 ), OC(R 18 R 19 ), SC(R 18 R 19 ), N(R 20 )C(R 18 R 19 ) wherein R 18 , R 19  and R 20  represent C1 through C6 groups, or phenyl groups which may have substituents, OCO or CO 2 CH 2 ; w represents an integer of 0 or from 1 to 2 wherein Y may be identical or different when w is 2; and u represents 2 or 3 wherein Y, R 13  and w may be identical or different. 
     
     
       48. The process for producing the star block copolymer according to  claim 45 , characterized in that the compound capable of copolymerizing with the compound represented by the general formula (VII) is a compound represented by the general formula (VIII):                    
       wherein R 6 , R 7 , and r are the same as mentioned above. 
     
     
       49. The process for producing the star block copolymer according to  claim 45 , caracterized in that the compound capable of anion polymerizing is a compound represented by the general formula (IX):                    
       wherein R 8  and R 9  are the same as mentioned above.